The majority of present day integrated circuits (ICs) are implemented by using a plurality of interconnected field effect transistors (FETs), which may be realized as metal oxide semiconductor field effect transistors (MOSFETs or MOS transistors). A MOS transistor may be realized as a p-type device (i.e., a PMOS transistor) or an n-type device (i.e., an NMOS transistor). Moreover, a semiconductor device can include both PMOS and NMOS transistors, and such a device is commonly referred to as a complementary MOS or CMOS device. A MOS transistor includes a gate electrode as a control electrode that is formed over a semiconductor substrate, and spaced-apart source and drain regions formed within the semiconductor substrate and between which a current can flow. The source and drain regions are typically accessed via respective conductive contacts formed on the source and drain regions. Bias voltages applied to the gate electrode, the source contact, and the drain contact control the flow of current through a channel in the semiconductor substrate between the source and drain regions beneath the gate electrode. Conductive metal interconnects (plugs) formed in an insulating layer are typically used to deliver bias voltages to the gate, source, and drain contacts.
Stress liners are often used to enhance the performance of MOS transistor devices. For example, tensile stress liner material may be formed overlying NMOS transistor devices and compressive stress liner material may be formed overlying PMOS transistor devices. Tensile plasma enhanced nitride (TPEN) is commonly used as a tensile stress liner material. Some fabrication processes cure the TPEN liner with ultraviolet (UV) radiation to enhance the tensile properties of the TPEN liner material. The penetration depth of the UV radiation may not be sufficient to uniformly cure the TPEN liner, due to the topology of the transistor devices.
Existing techniques and processes that address the non-uniformity of UV-cured TPEN liners are inefficient, complex, time consuming, and/or costly. Accordingly, it is desirable to have an effective and cost-effective solution to the problem of non-uniform UV-cured TPEN liner material.